Combined thermostat and automatic pilot control



1 M. J. CAPARONE ETAL 68 COMBINED THERMOSTAT AND AUTOMATIC PILOT CONTROL Filed May 15, 1951 5 Sheets-Sheet l J50 INVENTORS 146 14a (Wax/.454 J. C4 PARoMg By CAHRL E8 (*7. V ushw.

1953 M.J. CAPARONE ET AL ,658,.686

COMBINED THERMOST'AT AND AUTOMATIC PILOT CONTROL.

Filed May 15, 1951 3 Sheets-Sheet 2 NOV. 10, 1953 J CAPARQNE ETAL 2,658,686

COMBINED THERMOSTAT AND AUTOMATIC PILOT CONTROL;

Filed May 15, 1951 3 Sheets-Sheet 3 Patented Nov." 10, 19 53 COMBINED THERMOSTAT AND AUTOMATIC PILOT CONTROL Michael J. Caparone, Arcadia, and Charles M.

Vaughn, LosAngeles, Calif., assignors to Robertshaw-Fulton Controls Company, Greensburg, Pa., a corporation of Delaware Application May 15, 1951, Serial N 0. 226,506

4 Claims.

This invention relates to combination controls for gaseous fuel burners and more particularly to controls wherein the temperature controlling de- "vice and the safety shut off both operate on the same control valve and the safety shut-off device also operates a pilot valve.

The present invention is characterized by a movable electromagnet which picks up its armature in response to energization by a condition responsive device when the electromagnet is moved into engagement with the armature, the electromagnet with the armature in its attracted position returning to its initial position upon completion of this resetting operation. With the armature in attracted position, the control valve is free to be moved between closed and open positions by the thermostat which may be of the 'rod-and-tube type operating through a snap-action mechanism. However, when a preselected condition is established, such as the extinguish- 'ment of the pilot flame, the electromagnet is deenergized and the armature is released to return under spring bias to its original position. The 'return movement of the armature. is in a path substantially coaxial with the valve member so that the latter is moved to closed position should the thermostat be holding it open. In this respect, the control is similar to that disclosed and claimed in the copending application of Wilbur F. Jackson; Serial No. 98,486, 'filed June ll, 1949, now Patent No. 2,604,266. Th pilot valve is disposed laterally of the electromagnet and has an operatingmember operatively associated therewith for positioning the pilot valve to admit fuel tothe pilot burner only during the resetting operation and while the armature is in attracted position. l

It is a principal object of this invention to provid' 100% shut-oil of fuel to all burners upon failure of the pilot flame.

, Another object of this invention is to prevent now of fuel to the main burner while permitting flow of fuel to the pilot burnerduring the resetting operation. w e

" Other objects and advantages willappear from the following specification taken in conjunction withthe accompanying drawings wherein:

"f Fig. 1 isa plan view of a control device embodying this invention with a portion "thereof.

f shown in section;

.Fig. 2 is a sectional view takenon the line' nnorrig. 1;; y

fFig. 13 is afragmentary sectional view taken on ne u e ns-1n or Fig. 1; and

a FigSQfl an e arefsimilar to Fig.1 13 with t parts in the passage I6.

communication by means scribed.

of the device shown in different operating positions.

Referring to Figs. 1 and 2, the control device structure comprises a casing It provided with an inlet 12 and an outlet it connected by a main fuel passage IS. The flow of fiuid fuel in the passage I6 is under the control of a thermostatically controlled valve 58 which has associated therewith a safety shut-off device 29 operable in response to a predetermined condition for preventing flow of fuel through the passage I6.

Interposed in the passage it between the inlet [2 and the thermostatically controlled valve [8 isa main shut-off valve 22 which is movable between positions for controlling the flow of fuel The main shut-off valve 22 may also control the flow of fuel to a filter chamber 24 containing a filter 26 and communicating with an auxiliary passage 28 formed in the casing H] which passage in turn communicates with the trolling the flow of fuel to a pilot burner (not shown). The pilot valve 30 is operatively associated with the safety shut-off device 20' as will more fully appear.

The thermostatically controlled valve l8 may comprise a partition 32 traversing the passage [6 and having a port 34 formed therein. A valve seat 36 formed on the partition 32'around the port 34 is cooperable'with a reciprocable valve member 38 to close the port 34. The valve member 38 ishere shown as being of the disk type and mounted upon a hollow valve stem 40 which slidably extends through an axial hollow boss #2 carried by the casing it in axial alignment with the port 34. The port 34 in the partition 32 provides communication between the main fuel passage l6 and the outlet I4 and the valve member 38 is normally biased toward the seat to close such to be more fully de- The hollow valve stem contains an override *mechanism comprising a plunger l-l and biasing spring 56 which serves to urge a collar 48 on the 54 formedin the casing I0 withthe port 34. j5l imparts a snap-action movement to thevalve 'plunger. 44 into engagement with a bushing 50 'closing the inner end of the hollow valve stem 46. The plunger 44 projects through the bushing 50 ,for operative engagement with a snap-action mechanism 5! of well known form including a thrust element 52 which is disposed in a recess in axial alignment The snap-action mechanism member SB in a manner well known in theart. Thermally responsive actuating means isproengages at its inner end with the magnet cover 94. A coil spring I26 is housed within the butthe auxiliary or pilot valve 30 is operatively associated with the electromagnetic shut-off device so that the pilot valve is in open position only while the resetting means isin operation and while the armature H6 is in the attracted position.

valve chamber I30 formed in the casing I0 laterally of the annular boss '84. The pilot valve chamber I 30 communicates with the auxiliary in one position of the valve member I 62, to reg- The pilot valve 30 may take the form of a pilot passage 28 and with a pilot passage I32 formed :3:

in the casing I0 and communicating with an outlet I34 adapted for connection to the pilot burner (not shown). The rate of flow through the pilot passage I32 may beregulated by the usual needle valve I36 of any suitable form.

An annular valve seat member I38 is positioned in the valve chamber I30 in threaded engagement with the walls thereof to intercept flow of fluid therethrough and is provided with a centrally disposed valve port I 40 having a circular 1 cross section. slidably carried in the valve port I40 is a non-circular valve stem I42 which carries a disk valve member I44 at one end. A spring I46 acting between the valve member I44 and a cap I48 threaded into the open end of the valve chamber I30 serves to bias the valve memher I 44 toward the valve seat member I38.

When the valve member I44 is in its biased position and in engagement with the valve seat member I38, fluid flow through the valve chamber I30 is prevented. Conversely, when the valve member I44 is positioned away from the valve seat I38, fuel is permitted to flow from one side of the valve seat member I38 to the other side thereof through the valve port I40, passing between the surface of the non-circular valve stem I42 and the walls of the port I40. Communication is established between the pilot passage I32 and the valve port I40 by an annular groove I50 formed in the valve seat member I38 to register with the pilot passage I32 and connected to the valve port I40 by a plurality of radially extending bores I52. Thus, fuel flowing through the valve port I40 passes through the bores I52, the groove nular boss 84 to alternatively contact the end portion I I4 of the magnet cover 94 or the peripheral surface of the flange I20 as will be more fully brought out in a discussion of the operation of the device.

The main shut-off valve 22 is here shown as being of the plug type and comprises a tapered valve seat I60 formed in the casing I0 for receiving a plug valve member I62. The valve member I 62 is provided with an angular passage I64 one end of which is in constant communication With the inlet I2 and the other end of which forms an opening I66 in the side of the valve member I62. The opening I66 is adapted to be closed by the surface of the valve seat I60 ister with the opening to the pilot filter chamber 24 in another position of the valve member I62 to provide a Pilot position, and to register with the passage I6 and the opening to the pilot filter chamber 24 in still another position of the valve member I62 to provide a full-open or on position in a manner well known in the art.

Interposed between the valve member I62 and a cover plate I68 secured to the casing I0 is a .1 spring I10 which serves to bias the valve member I62 against the valve seat I60 sufficient to establish a fluid sealing but rotatable relation therebetween.

Rotatably mounted in a bore I12 formed in the valve member I62 along the axis thereof is a I50, and the pilot passage I 32 to the pilot burner 1 (not shown) so that the flow of fuel to the pilot burner is controlled by thevalve member I44.

The end of the valve chamber I30 opposite the end closed by the cap I48 registers with a bore I54 formed in the casing I0 and opening into the interior of the annular boss 84. Communication between. the valve chamber I30 and the interior of the annular boss .84 is prevented by a flexible sealing disk I56 which is clamped shaft I14 which extends into the passage I64 and into engagement with the adjusting element 18 of the thermostat. A slot I16 formed inthe adjusting element 18 slidingly receives a rectangular extension I18 ofthe shaft I14 to provide a slidably torque transmitting connection between the shaft I14 and the adjusting element 18. Ro

tation of the shaft I14 will thus produce rotational and consequent axial movement of the adjusting element 18 without corresponding axial movement of the shaft I14. Leakage through the bore I12 is prevented by a suitable stuffing box I80.

To provide for rotation of the shaft I14, a rotatable control element or knob I82 is affixed to that end of the shaft I14 which extends out of the valve member I62. The knob I82 is mounted on the shaft I14 to be rotatable therewith and movable axially thereof through a limited distance and is provided on its underside with an annular groove I84. A coil spring I86 acting between the cover plate I68 and the knob I82 extends into the groove I84 and serves to bias the knob I82 to the outermost end of the shaft I14 and into engagement with a plate I88 which is secured to the end of the shaft I14 by a screw I9 When the knob I82 is retained by the spring I86 in its biased position bearing against the plate I68, the knob I82 and its associated shaft across the open end of the valve chamber I30 by the annular valve seat member I38. Abutting one side of the flexible disk I56 is the free end of the valve stem I42 and abutting the other side of the disk I56 is one end of an operating member here shown as a pin I58 slidably carried 1 in the bore I54. The axes of the bore I54 and the pin I58 are substantially normal to the axis of the armature stem H8" and the other end of the pin I58 extends into the interior of the an- I14 are free to rotate relative to the valve member I62. However, clutch means is provided for establishing a torque transmitting relation between the knob I82 andthe valve member I62 when the knob I82 is moved axially of the shaft I14 against the bias ofthe spring I86 to a depressed position. The clutch means may take the form of a single clutch tooth I92 depending from the underside of the knobI82'to be movable therewith into a complementary recess I94 formed in the valve member I62, engagement of the clutch tooth I92 with the walls of the recess I94 being effective to establish a positive driving connection between the knob I82 and the valve member Ifiz when therknolo 482 is in its depressed position.

It-willbe apparent that the knob-Jihisefiective in its biased position to adjust the temperature setting of the thermostat withoutrdisturbing the setting of the valve member 4-62 while I in its -;depressed position, i itis-effectivetozadjust the posit-tionof the valve member L62. The=,.comblnati0.n shut-off cock and thermostat -;adjusting device of the type herein disclosedis fullydisclosed and claimed in the copending application of Samuel G. Eskin and Adele M. Arkely-an, Serial =No. 230,612, filed June ;8, 1. 1951.

-* @peration When noefuel'is flowing to the maineor pilot burners, the various parts of the control device arepositioned as shown in Fig. 5. The. armature I II6 is in its released-position with the [armature stem H8 acting-underthe-bias:of the spring-H9 to' hold the valve member .38 against :the "valve seat36 andl-the pin 'I-58'engaging the ,inturned end portionv I I4 of the magnet covet-94 to; permit the pilot valve member I44 to engage the valve seat I38 under theJoiasof the spring I46.

Tor place the control device in operative condition the knob I82 is depressed and ;rotated to position the valve member I52 to the -Pilot position wherein: the angular passage I I 64 establishes communication .betweenthe inlet I2 and the pilot filter chamber I24. Insuch position of the valve member 162, fuel ;will flow from the inlet I2 through the angular passage H34 .in the valve member I62,-the filterifi in the filter chamber 24 and through the passage 1 2B to the pilot :valve chamber l I30. H

.The resetting operation is then conducted by I applying manual,pressure tothe button l24-for moving the magnet cover'94 and the magnet I jointly relativeto the armature I lfi to position 'showninlFig. .4. Duringathis. movement the coil springs QG and IIB are compressed, :andthe .pin 'I58 is forced to ride up the frustro-conieal surface of the inturned enct portion I I4-ofthe magnetcover 94 the end portion I I4-acting asia; cam

surface. 7 V I The pin I58-is,thus movedlaterally relative to the armature stem [l8 to move .thetvalve stem I42 against the biasofthe spring I46to position 7 the pilot valve-member I44 in its; open-position away' from the valve seat I38. Fuel will then flow throughtthevalveport I40,-bores I52, groove I50, and pilots passage. I32 to thepilot ,burner. (not shownlwhere it may. be-igniteda-by-a match or the like.

"The flame atlthe pilotburner may (heat, the hot junction'of the thermocouple (not shown) .eto causethe same to develop vsufieient-currentto energize the winding I 04 of the electroma net. The reset button I 24 is then releasedand the. bias of the springs-96 serves to retract the: magnet Covera l-and the magnet .I no vto theirinitial' positions. However, the-armatureaI-IG is nowcarried along with the: magnet 1:00 andithe. coil spring II 9 is retained in its compressed. condition. The

V variouspar-ts of-the device arenow asashown in is freed for movement to "open :positionarelative to the valve seat-r236. it will alsobe apparent r thatzawhen the=arniaturexII6 is 2.in::'its attracted stem Ililmoves relatively to the plunger during :r mainm tcon iguous to the ;.inturne nd porien 5H4 of the :ma ne Qve :9

Thus, upon completion'of the resetting operation, the-flange k2flli mesitienedrtotae e th pin: I58 to pre the pin I58 from riding down the flllStOr-CQIliCfil .eamrsur ae -eoflth en lpor ienq 'l l f he ma n cever s l :understhe b a Qf thesprin 1 an the valvememb zl 44ziima ntained ins op n p tion.

:Th a 'v lve mem e i -may now be roated it a-nes tm whe e n h angular pa sa I64 formed therein is in communication witlrthe inlet I2, the;pilot filterchamber-24-and themain fuel passage l6.

Upon ademandzfor heat, the rod .58 exerts a force on the thrust element 52 ofthesnap-aetion mechanism 5| and the snap-action mechanism opens the valve member 38 against the biasof the .valve spring 92. Flow of fuel tromthe inletvlz through themain-IueLpassage I5 andthe valve port 34 to the outlet I4 is now permitted and operationof. the main burner in the usual manner can occur. I

'When the temperature sensed by the thermostat 56, 58 reaches that for which the adjustment has been, -set, closure of the valve'member -38 occursunder 'bias of the spring 92 and is per- ;mitted due .to reversepositioning ofithe snapaction mechanism as is Well known to those skilled in the art. During-this; normal reciprocation of' the valve member-38in controlling flow of fuel to. the outlet I4, the armature I I6 remains engaged with-the pole facesof the-magnet Illa;

In the event that the flame at the pilot burner is extinguished, the supply of current ;-to the electromagnet will be cut off and upon deenergization of-the electromagnet, the armature l I6 will move away from the pole faces-ofthe magnet 100. Such movement of the armature H6 is due tothebias-of the .coilspring I I-QSand serves to-bring the armaturelstem II8-;into operative en a ement withl' herrive ca r e b h seaing disk toforce the rivet; 90 into engagement with the :valve member 138. and cause ,closure thereof. --As.previous1y indicated, such closure will :occur regardless; of-Iwhether the thermostat 56,258 is operated-to hold thevalvememherjS inopen positiondue tothe provisionvoii the over? ride connection within thethollow valve ;stem 549, the bias otthe override springz lfi being overcome upon release of the armaturel I6 by the stronger bias exerted by the coilspring H9. "The hollow compression of the overriderspring Mi -without causing reverse operation of I the snap-action mechanismfil as in normal thermostatic-operation. a

Movement-of the armature. I I5 trornattracted to released. position will also causes the armature stem I18: to move-relativerto the: pin I58. and carry theFflange IZILout-zof engagement with the pin IEB. Since .thepinil 58ris no longer restrained bytheflange l2l l,it is'moved laterallyrelativelto positiomandkthus movable-with the magnet wfl,

the flange I20 carried by the armature stem H8 the armatureustem H8 underthe bias :of the springuI46 to permit the pilot-valve-member I44 to: move into engagement with the, valveseat I38 therebycutting on the ,fiowof fuel to the pilot 7 burner. The variousipartsfof thecontrol device arev now positioned as sho-WninFig.1.5 and no. fuel canrflowztoanybf the burners. I I a nIt xvi-11 he apparentirorrrthebfore o111g that the illustrated embodiments provide shut off of fuel to all burners upon failure of the pilot flame. It will also be apparent that the illustrated embodiments prevent flow of fuel to the main burner while permitting flow of fuel to a pilot burner during the resetting operation and accordingly accomplish the objects of the invention. On the other hand, it will be understood that many changes may be made in the details of construction and arrangement of parts to accomplish the purposes of this invention without departing from the scope of the invention as defined in the appended claims.

It is claimed and desired to secure by Letters Patent:

1. In a control device, the combination of a movable electromagnet having an armature separable therefrom for movement between attracted and released positions, thermally responsive valve means movable between controlling positions independently of said armature and having perative engagement with said armature in said released position thereof, means for biasing said armature to said released position and holding said thermally responsive valve means in one of said controlling positions, resetting means operable for moving said electromagnet into engagement with said armature, means effective upon completion of the resetting operation for retracting said electromagnet and causing movement of said armature out of operative engagement with said valve means to free the same for movement to another of said controlling positions, auxiliary valve means movable between controlling positions, an operating member operatively associated with said auxiliary valve means and slidable laterally relative to said electromagnet, cam means movable with said electromagnet and engageable with said operating member during the resetting operation for placing said auxiliary valve means in one of said controlling positions, and detent means movable with said armature for retaining said auxiliary valve means in said one position while said armature is in said attracted position.

2. A control device as claimed in claim 1 wherein said electromagnet is mounted in a movable casing to be movable therewith, said cam means including a cam surface formed on said casing, said detent means including an element having a surface complementary with said cam surface and adapted to be positioned in engagement therewith while said armature is in said attracted position.

3. In a control device, the combination of a movable casing having an electromagnet mounted therein for movement therewith, said electromagnet having an armature separable therefrom for movement between attracted and released positions, thermally responsive valve means movable between controlling positions independently of said armature and having operative engagement with said armature in said released position thereof, means for biasing said armature to said released position and holding said thermally responsive valve means in one of said controlling positions, resetting means operable for moving said electromagnet into engagement with said armature, means effective upon completion of the resetting operation for retracting said electromagnet and causing movement of said armature out of operative engagement with said valve means to free the same for movement to another of said controlling positions, auxiliary valve means disposed laterally of said electromagnet, said auxiliary valve means being movable between controlling positions and biased to one of said positions, an operating pin operatively associated with said auxiliary valve means and slidable laterally relative to said electromagnet, a cam surface formed on said casing and engageable with said pin during said resetting operation for moving said auxiliary valve means against said bias to another of said controlling positions, and detent means movable with said armature and cooperable with said pin for retaining said auxiliary valve means in said other position While said armature is in said attracted position.

4. A control device as claimed in claim 3 wherein said detent means includes an element having a surface complementary with said cam surface and adapted to be positioned in engagement therewith while said armature is in said attracted position.

MICHAEL J. CAPARONE. CHARLES M. VAUGHN.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,290,108 Mantz July 14, 1942 2,542,127 Ewing Feb. 20, 1951 

